In machines for metal cutting such as machine tools, especially turning machines (such as lathes), material is typically removed (or cut) from an exterior or interior surface of a work piece by rotating the work piece and by moving a cutting tool towards the work piece in an axial and/or radial direction. The case where the cutting action provided by the cutting edge of the cutting tool is performed on an interior surface of the work piece (i.e. from inside a hole of the work piece) is sometimes referred to as boring. Knowledge of the position and orientation of the cutting edge of the cutting tool is important for providing high precision machining. In some cases, even a small deviation in the position or orientation of the cutting edge may reduce the machining precision below an acceptable level. The cutting edge of the cutting tool is often a cutting edge of an insert mounted at a cutting head of the cutting tool. The orientation of the cutting edge may for example be determined via knowledge of the orientation of the cutting tool, or by measuring the orientation of the cutting edge itself. Some cutting tools have a planar surface on which a spirit level may be placed for checking that the cutting tool has been mounted at the correct orientation. However, this may require the user to adjust the orientation of the cutting tool by one hand while the other hand holds the spirit level in position. Generally, the process of establishing proper orientation of the cutting tool may be complicated and/or time consuming. It may for example require certain skill by the person mounting the cutting tool. It would therefore be advantageous to provide a new way to estimate the orientation of cutting tools.